Cylinder covers for fluid pressure cylinders

ABSTRACT

In a fluid pressure cylinder wherein a plurality of tie-bolts are fitted through a pair of covers, attached at both ends of a cylinder body, and clamped thereto by a plurality of nuts, the covers are provided with a plurality of recesses of the corner portions for lodging therein the clamping nuts; after the cylinder body and the covers are clamped together by said nuts, a fitting plate is mounted separately on at least one of the covers, and is attached by further nuts.

O United States Patent [191 [111 3,738,232 Kado 1 June 12, 1973 1 CYLINDER COVERS FOR FLUID PRESSURE 3,200,717 8/1965 Einsiedler 92/161 Y IN 2,894,489 7/1959 Clay 92/161 75 I t T n h. K d 0 k J 3,323,820 6/1967 Braccini 287/189.36 F

n l 1 i or t a 5a OTHER PUBLICATIONS [73] Asslgnee: i Ortman Miller Machine Co. Catalogue of Series TH Kitaeguchi-cho, l-ligashiyodo-ku, Hydraulic Cylinders Osaka, Japan [22] Filed: June 22, 1970 Primary Examiner-Milton Kaufman Assistant Examiner-Ronald l-l. Lazarus [21] Appl' 47953 Attorney-Tab T. Thein [30] Foreign Application Priority Data [57] ABSTRACT June 20, 1969 Japan 44/59056 In a fluid pressure cylinder wherein a plurality of tiebolts are fitted through a pair of covers, attached at [52] US. Cl. 92/161, 92/169, 287/189.36 F both ends of a cylinder body, and clamped thereto by [51] Int. Cl. F0lb 29/00 a plurality of nuts, the covers are provided with a plu- [58] Field of Search 92/ 161, 164, 169; rality of recesses of the comer portions for lodging 287/l89.36 F therein the clamping nuts; after the cylinder body and the covers are clamped together by said nuts, a fitting [56] References Cited plate is mounted separately on at least one of the covers, and is attached by further nuts.

7 Claims, 7 Drawing Figures PAIENIEDJIINIZW 31.232

SHEEI 1 W 2 INVENTOR A/I /W KA 00 CYLINDER COVERS FOR FLUID PRESSURE CYLINDERS In conventional fluid pressure or power cylinders, a cylinder body, one or two covers and fitting plates are usually assembled by means of a single group of nuts or by means of internal threads, without providing recessed spaces for the nuts.

In the former case it is necessary to remove the nuts on the occasions of mounting or demounting the fitting plate, and this has bad influence on the air-tightness between the cylinder body and the covers, the latter being clamped by means of tie-bolts or rods and the aforementioned nuts.

In the latter case the arrangement is inconvenient in transportation and storage, and has the same disadvantages as the former when mounting and demounting the fitting plate because the latter must be formed integrally with the cylinder body and the covers.

It is an object of this invention to provide a cylinder cover which has good air-tightness between the cylinder body and the covers even in case of frequent mounting and demounting of the fitting plate or plates.

According to one of the major features of the present invention, this is accomplished by providing separate recesses or spaces for the nuts which clamp the body and the cover, a second set of nuts being provided for separately clamping the fitting plate to the respective cover.

The fitting plate is separate from the associated cover, has therein bores corresponding in number and location to the tie-rods, and is adapted to be mounted independently on the cover on its side facing away from the cylinder body.

The fitting plate is preferably provided with depressions or recess of its own for its own clamping nuts, without any part of the structure protruding beyond the outer surface of the fitting plate.

The inventive separate fitting plate is either planar or L-shaped in configuration. In the latter case, the overall height of the plate may be less than that of the respective cylinder cover.

Other objects and many of the attendant advantages and features of the invention will be readily appreciated as the same becomes better understood by reference to the following detailed description, when considered with the accompanying drawings, wherein FIG. 1 is an isometric view showing a portion of the outside of a first exemplary cylinder cover according to the present invention;

FIG. 2 is a partially broken side view showing a fiat fitting plate attached to the cover of FIG. 1;

FIG. 3 is an end elevational view corresponding to FIG. 2;

FIG. 4 is a partially broken side view, similar to FIG. 2, but showing a modification with an L-shaped fitting plate;

FIG. 5 is an end elevational view corresponding to FIG. 4; and

FIGS. 6 and 7 are respective side elevational views of well known cylinders and fitting plates, similar to the inventive embodiments of FIGS. 4 and 5 as well as l to 3, respectively.

First the prior-art structures will be described. Taking FIG. 7 first, it shows a conventional cylinder cover 11 secured to one end of a cylinder body 17 by means of a number of tie-bolts or rods 14; it will be understood that another cover (not shown) is usually disposed at the other end of the cylinder body. A conventional fitting plate 15 is mounted on the outside of the structure, the tie-rods 14 being secured thereto by means of internal threads 13, as shown.

Taking now the variant of FIG. 6, this shows a similar structure of one or two covers 11 flanking cylinder body 17, tie-rods 14 passing through appropriate bores in the covers, and having an L-shaped fitting plate 15 attached to one or two of the tie-rods, by means of an appropriate number of nuts 16.

In the latter case, it is necessary to remove the nuts 16 on the occasions of mounting or demounting the fitting plate 15'; in the former case it is similarly inconvenient to mount or demount the fitting plate 15 because the latter must generally be formed integrally with the respective cover 11 and/or the cylinder body 17.

The inventive cylinder covers avoid the disadvantages of the prior art in providing separate fitting plates as shown in FIGS. 2 and 3 for a first inventive embodiment, and as illustrated in FIGS. 4 and 5 for a modified or second embodiment.

The first exemplary cylinder cover according to the invention is shown in FIGS. 1 to 3 wherein a cover 1 is shown attached to one end of a cylinder body 7 (a second cover is omitted at the broken-away end of the body). A number of tie-rods or bolts 4 is passed through appropriate bores of the cover 1 which is provided with a corresponding number of recesses 1b wherein nuts 2 are threadedly secured to the outer ends of the tie-rods 4.

The cover 1 has a peripheral abutting or contact surface la to which is fitted a planar fitting plate 5 (see FIGS. 2 and 3). The latter has therein depressions or recesses 5b similar to recesses lb of the cover 1, for lodging outer or further nuts 6 threadedly engageable with the terminal portions of the tie-rods 4 (in FIG. 2 the latter are shown to protrude further beyond the cover 1 than in FIG. 1 where no plate is fitted).

FIG. 3 shows an end elevation of the complete assembly, also illustrating a central passage or opening 5a in the plate 5 through which a piston rod (not shown) or the like can protrude into the inner space within the cylinder body 7.

FIG. 1 also shows a central portion 8 of the fluid pressure cylinder through which the conventional inlet and outlet ports lead into the operative inner space (only schematically illustrated).

In the illustration of the modified or second exemplary embodiment only the side and end elevational views are given, FIGS. 4 and 5 being thus similar to the just discussed FIGS. 2 and 3, respectively. A cover 1 is again illustrated at one end of body 7, with a number of tie-rods 4 passing through bores of the cover and having inner nuts 2 secured to the ends of tie-rods 4, within recesses 1b, as described before.

In this structure a smaller fitting plate 5' is used which is substantially L-shaped, as shown. No recesses are required in this case for the outer or further nuts 6 since the latter are well within the projection of the plate 5 which, as can be seen, has bores or other conventional attaching means therein.

The fitting plate 5 is also provided with a central passage as described for plate 5, and it is preferably provided with one or more locating lugs 5c in the form of pressed-out or bent portions which provide abutting surfaces against the lower edge of cover 1.

The cylinder covers 1 are preferably made of castings. As a matter of example, four symmetrically arranged tie-rods 4 are shown in both exemplary embodiments, with the appropriate recesses lb and 5b, as well as the nuts 2 and 6, preferably disposed at each corner edge portion of the covers 1. It will be understood however that a smaller or larger number of these elements can also be provided.

The provision of the inner nuts 2 allows the covers 1 to remain in constant assembly with the body 7 while the fitting plates 5, 5' may be removed and reassembled at will, by means of the outer nuts 6, without disturbing the basic structure. The abutting surfaces la provide an air-tight contact with the plates 5, 5. Preferably, bulgeforming or other pressing processes are used for economically producing the fitting plates according to the invention.

According to the provision of the recesses 1b for the inner nuts 2, and the separate attachment of the fitting plates 5, 5 by the outer nuts 6, the covers 1 do not have to be separated from the cylinder body 7. Mounting and demounting operations are thus greatly simplified, and the air-tightness between the body 7 and the covers 1 is ensured at all times.

Because the corner edges of the covers 1 are originally formed unnecessarily thick, there are no irrational dynamic forces even if the nut spaces 1b are provided in a recessed manner in these cover portions. The inventive structure eliminates unnecessarily thick portions in the covers, and thus reduces the overall weight of the cylinders.

Most of the fabricating steps can be performed by casting, for example from an aluminum alloy; the inventive covers are thus simple in fabrication and have a strong structure, a fine appearance and they can be mass-produced.

It is an advantage of the invention that the fitting plates can be readily interchanged so that plate 5 can be substituted on the cover 1 by plate 5', and vice versa. In other words, either the flat or the Lshaped plate can be used regardless of the arrangement of the cylinder body and covers as long as the recessed portions 1b of the latter are provided to lodge the inner nuts 2.

The earlier discussed prior-art structures do not present the above-described advantages. With the known fitting plates 15, as described in connection with FIGS. 6 and 7, it is possible to fix only one plate on the respective cover 11, and it is also possible to fix a plate only at either side of the cylinder.

According to the present invention it is however possible to apply either of the fitting plates 5 and 5 to the respective cover 1 at either the rod end or the head end of a cylinder, and to provide a piston rod through the central passage 5a of either plate 5 or 5.

The fitting plates of the present invention can be made, by press forming. The interchangeability of these plates is more effective on account of the bulging of the recesses or nut seats 5b for the outer nuts 6, as shown in FIGS. 2 and 3 for plate 5, and similarly by means of bulging the locating lugs or abutting surfaces 50 of plate 5, as shown in FIGS. 4 and 5, to match suitable cylinder covers.

It should be understood, of course, that the foregoing disclosure relates only to preferred embodiments of the invention and that it is intended to cover all changes and modifications of the examples described which do not constitute departures from the spirit and scope of the invention.

What I claim is:

l. A cylinder cover arrangement and a fluid pressure cylinder, the latter having a body receiving a cover at each end, a piston rod reciprocable in said body, a plurality of tie-rods through appropriate bores of said cover and extending along said body, a plurality of first nuts threadedly engaged with said tie-rods outside said cover, for clamping the same and said body therebetween, wherein said cover has marginal recesses corresponding in number to that of said tie-rods and said first nuts, lodging the latter in a recessed manner, a fitting plate separate from said cover and having therein bores corresponding in number and location to that of said tie-rods, mounted onto said cover on the side of the latter facing away from said body, and a plurality of second nuts threadedly engaged with said tie-rods outside said fitting plate, providing releasable attaching means for said cylinder by the intermediary of said fitting plate, wherein the latter has depressions therein lodging said second nuts in a recessed manner, without any part protruding beyond the outer surface of said fitting plate.

2. The cylinder cover arrangement as defined in claim 1, wherein said cover and said fitting plate have substantially planar abutting surfaces which provide an air-tight seal when said cylinder is assembled with said fitting plate.

3. The cylinder cover arrangement as defined in claim 1, wherein said fitting plate has a central cut-out therein, allowing the passage of said piston rod therethrough.

4. The cylinder cover arrangement as defined in claim 1, wherein said fitting plate is of substantially planar configuration.

5. The cylinder cover arrangement as defined in claim 1, wherein said fitting plate is in the form of an L-shaped bracket.

6. The cylinder cover arrangement as defined in claim 5, wherein the height of said fitting plate is less than that of said cover.

7. The cylinder cover arrangement as defined in claim 5, wherein said fitting plate has at least one locating lug protruding therefrom for immobilizing the same with respect to said cover.

l l t 

1. A cylinder cover arrangement and a fluid pressure cylinder, the latter having a body receiving a cover at each end, a piston rod reciprocable in said body, a plurality of tie-rods through appropriate bores of said cover and extending along said body, a plurality of first nuts threadedly engaged with said tie-rods outside said cover, for clamping the same and said body therebetween, wherein said cover has marginal recesses corresponding in number to that of said tie-rods and said first nuts, lodging the latter in a recessed manner, a fitting plate separate from said cover and having therein bores corresponding in number and loCation to that of said tie-rods, mounted onto said cover on the side of the latter facing away from said body, and a plurality of second nuts threadedly engaged with said tierods outside said fitting plate, providing releasable attaching means for said cylinder by the intermediary of said fitting plate, wherein the latter has depressions therein lodging said second nuts in a recessed manner, without any part protruding beyond the outer surface of said fitting plate.
 2. The cylinder cover arrangement as defined in claim 1, wherein said cover and said fitting plate have substantially planar abutting surfaces which provide an air-tight seal when said cylinder is assembled with said fitting plate.
 3. The cylinder cover arrangement as defined in claim 1, wherein said fitting plate has a central cut-out therein, allowing the passage of said piston rod therethrough.
 4. The cylinder cover arrangement as defined in claim 1, wherein said fitting plate is of substantially planar configuration.
 5. The cylinder cover arrangement as defined in claim 1, wherein said fitting plate is in the form of an L-shaped bracket.
 6. The cylinder cover arrangement as defined in claim 5, wherein the height of said fitting plate is less than that of said cover.
 7. The cylinder cover arrangement as defined in claim 5, wherein said fitting plate has at least one locating lug protruding therefrom for immobilizing the same with respect to said cover. 